git-id c4acb2c0669c5c5c9b28e9d02a34b5c67edf7092 attempted to limitnewidle critical section length by stopping after at least one taskwas moved. Further investigation has shown that there are otherpaths nested further inside the algorithm which still remain that allowlong latencies to occur with newidle balancing. This patch appliesthe same technique inside balance_tasks() to limit the duration ofthis optional balancing operation.